The present invention relates to borescopes or endoscopes, and is more particularly directed to a consolidated control handle and viewing screen for a video borescope or endoscope or the type having a remotely articulated tip.
Borescopes or endoscopes of this type have a flexible elongated insertion tube, which can have a miniature video camera situated within its distal tip, or alternatively can have a fiber optic imaging system, and a video camera positioned at a proximal end of the unit. A borescope is an industrial type device intended for inspection of inaccessible areas of a complex machine or device, such as the tubes of a boiler or the vanes of a gas turbine. An endoscope is a medical device which can be inserted into a body cavity, e.g. the esophagus or colon, for diagnostic or surgical purposes. A laparoscope is a specific type of endoscope in which the insertion tube enters the body through an incision. The laparoscope usually has a rigid insertion tube which can have an articulated portion near its distal tip.
The borescope or endoscope has a control section at the proximal end of the insertion tube for remote bending or flexing of the distal articulation section. Frequently, the articulation section is cable actuated, and there are two pairs of steering cables that extend through the insertion tube from the control section to the distal articulation section. In one typical configuration, there is a rack and pinion mechanism in the control section which is actuated by a pair of steering knobs for manipulating the steering of the distal tip in two crossed planes disposed at ninety degrees. These are typically in the X direction (corresponding to left and right movement) and the Y direction (corresponding to up-and-down movement). One or both pairs of cables are differentially displaced for moving the tip of the borescope or endoscope to facilitate visual inspection of an object.
Light for illumination is conveyed from an external light source over a fiber optic bundle that passes through the insertion tube.
Endoscopes and borescopes of this general type have been described in Moore et al. U.S. Pat. No. 4,253,447; Moore et al. U.S. Pat. No. 4,261,344; and Danna et al. U.S. Pat. No. 4,491,865.
A recent proposal has been to employ joystick controlled motor devices to move the two pairs of steering cables, where the motor drives are incorporated in the housing of the control section. One such arrangement is proposed in U.S. Pat. No. 4,503,842.
In a typical video type borescope or endoscope, an umbilical tube extends proximally from the control section and connects to a video processor and video monitor. According to the specific system, the monitor can provide a full color image or a black-and-white image of the object in the viewing field of the video camera. The monitor is either incorporated into the video processor or provided in a separate cabinet. This aspect limits the portability of the system by requiring the monitor to be carried, and space needs to be provided for it in the carrying case. Moreover, it is often inconvenient for the operator to use a conventional monitor, because he or she must continually direct his or her attention back and forth between the monitor and the control handle.
A technique of measuring objects in the field of view of the viewing camera has been describe in Salvati et al. U.S. Pat. No. 5,070,401. In that system, measurements of the object, e.g., its width, slant length, and depth, can be calculated from information on the screen without need to impose a scale next to the object to be measured. This technique requires an electronic system for automatically carrying out the necessary measurements, based upon pre-programmed algorithms. The system is operated from a keyboard in conjunction with a joystick, mouse, trackball or similar device to move a marker or cursor on the screen. These control devices, namely the keyboard and the joystick device, are also separate elements and have to be located at some distance from the control handle. This makes it somewhat inconvenient to carry out the measurement technique.